Laminates of a backing or facestock, pressure sensitive adhesive and a scored release liner all have been made available to the art in continuous rolls for processing directly into labels by guillotining or matrix cutting or by subdivision into sheets of convenient size such as 81/2".times.11" or 81/2".times.14" or metric sheets of similar dimension for printing by offset printing and subsequent conversion by guillotining and/or matrix cutting to form labels. The labels have a brittle zone or score on the release liner, which upon bending forms a crack to allow sections of the release liner to be removed, exposing the adhesive for application to a substrate.
Scoring is particularly important in guillotined labels. Scoring has been chemical as described, for instance, in U.S. Pat. No. 3,006,793 to Wheeler and U.S. Pat. Nos. 4,264,662 and 4,428,887 to Lacy et al incorporated herein by reference or mechanical as described, for instance, in U.S. Pat. No. 4,790,805 to Slobodkin incorporated herein by reference, and laser cut described, for instance, in U.S. Pat. No. 4,537,809 to Ang et al incorporated herein by reference.
The ideal scoring operation is to provide a score depth and pattern which allows a release liner to be removed on masse from the layer of the adhesive by a single break or crack formed on bending any available score to a point of fracture to allow removal of the release liner in two pieces from the entire sheet or a label cut from the laminate. removal of a release liner section containing multiple scores without breaking at a score is known as "pull across".
Desirably the scores are spaced in terms of the size of the labels to be produced from the laminate so as statistically each label will contain at least one score to avoid the time consuming practice of forming a separation in between the release liner and adhesive and pealing the release liner from the adhesive.
A conventional method for production of sheet laminates for use in conversion into labels has involved separate scoring of the release liner, moisturizing the release liner and facestock to equilibrate them with the atmosphere, forming the laminate and cutting the laminate into sheets of predetermined size. Typically the backing or facestock has been 60 lb. paper, the adhesive a solvent, emulsion or hot melt coated and the release liner formed of 63 lb. paper. The adhesive may be coated on the backing or the release liner. The release liner may be longitudinately scored as in the '805 patent or diagonally scored as described in U.S. Pat. No. 4,698,052 to Slobodkin also incorporated herein by reference.
The sheets cut from the stock as currently manufactured can not pass well through office copiers or desk top printers such as laser and dot matrix printers due to the tortuous path required for paper travel. To effectively show this, there is attached herewith FIGS. 1A 1B and 1C which respectively show the paper flow paths for CX, SX and LX series laser printers. With reference to FIG. 1A the most used path is "a-a" which is the most tortuous path. The easiest but least used path is "b-a". With reference to FIG. 1B the most used path is "a-a" again the most tortuous. The least used path is "b-a". With reference to FIG. 1C the most used path is "a-a" and the least used path is "b-b". The printer of FIG. 1A and 1B operate at 8 pages per minute while the printer of FIG. 1C operates at 4 pages per minute. Each provides a path which involves one or more sharp right angle or greater turns, which causes jams.
It would be desirable to form a laminate offering all the convenience of sheet stock cut for offset printing but which exhibit the ability to pass through the office copiers and desk top printers and the like and allow office printing of the sheet and cutting of the labels therefrom. This is the subject of the instant invention.